Multiple level lamp adapter

ABSTRACT

This disclosure relates to an electronic light dimmer of the phase control type. More particularly, it relates to a dimmer that is housed in an adapter socket interposed between a light bulb and a conventional socket.

United States Patent Rodriquez 1 July 22, 1975 [5 MULTIPLE LEVEL LAMP ADAPTER 3,331,013 7/1967 Cunningham 315/194 x 3,40l,265 9/1963 [75] Edward Rmlrlquel, Wmchesm 3,496,451 2 1970 Duncan 315/194 x Mass 3,573,543 4/1971 Grindstaff 315/194 [73] Assignee: Creative Technology Corporation,

a em ass Primary Examiner-John Zazworsky Filed: g- 5, 19 3 Attorney, Agent, or FirmCesari and McKenna [2]] Appl. No.: 388,459

[52] US. Cl 315/194; 3l5/l99; 315/200 R; [57] ABSTRACT 339/l76 L (12 H0513 13 39/00 This disclosure relates to an electronic light dimmer of [58] Field of Search 3 5/19 200 the phase control type. More particularly, it relates to 323/16; 339/136 S, I36 M, I76 L; 240/52 R a dimmer that is housed in an adapter socket interposed between a light bulb and a conventional socket, [56] References Cited UNITED STATES PATENTS 1/1967 Duncan .1 315/194 X 4 Claims, 3 Drawing Figures SHEET PATENTED JUL 22 ms PATENTED JUL 2 2 ms FIG.3

MULTIPLE LEVEL LAMP ADAPTER BAC KGROUND The advent of solid state switching devices such as silicon controlled rectifiers and triacs has materially affected both the design of light dimmers and the extent of their usage. Previously, the dimming of lights had been accomplished almost exclusively by means of variable transformers and variable inductors. These are fairly bulky and expensive devices and their use was therefore pretty much restricted to commercial applications. Solid state switches, on the other hand, can be incorporated into dimmers that are relatively inexpensive and small. They can, therefore, be fitted into conventional electrical outlet boxes in place of ordinary light switches, making them very suitable for residential applications.

Even so, many, if not most, of the residential applications are not well served by the solid state dimmers heretofore available. Specifically, those dimmers are not particularly suitable for use in table lamps or floor lamps, which are not connected to wall switches, but rather are plugged into electrical outlets. The switches in these lamps are sometimes contained in the lamp bases. More usually, they are incorporated into the bulb sockets. The present invention is directed to an adapter for a lamp of this type which provides the dimming function yet is small and unobtrusive as well as inexpensive.

SUMMARY OF THE INVENTION My lamp dimmer is in the form of an extension of the conventional light bulb socket. It has a base that screws into the socket and at the other end it has a socket into which the bulb can be screwed. The dimmer circuitry is entirely contained within this adapter and a control knob on the side permits the user to regulate the intensity of the light bulb. It will be seen that the adapter is quite short and thus unobtrusive, since it has the appearance of only a short extension of the original socket. Moreover, it is easily adjusted, since the control knob is in proximity to the conventional on-off switch incorporated in pre-existing sockets.

The dimmer is also characterized by both reliability and low cost, these features as well as the small size, largely resulting from construction specifically described below. For example, it includes a novel heat sink arrangement for the solid state switch. The switch is mounted on a metallic disk positioned against the base of the adapter. There it is substantially separated from the light bulb, which is the primary source of heat, and further it is ideally positioned for conduction of heat out of the adapter and into the lamp socket.

DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a perspective view, of a dimmer-adapter embodying the invention;

FIG. 2 is an exploded view of the dimmer-adapter;

and

FIG. 3 is a cut-away view of the dimmer-adapter.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIGS. 1, 2 and 3 a dimmer-adapter incorporating the present invention preferably has a onepiece molded housing of electrical insulating material, on which the various parts are mounted. The housing 10 has a lower cylindrical extension 12 over which a conventional lamp base 14 is fitted. A cavity 16 in the upper part of the housing is separated from a cavity 17 in the extension 12 by an integral plate 19. The cavity 16 contains a lamp socket shell 18.

In use the lamp base 14 is screwed into a light socket and a bulb in turn is screwed into the shell 18. An electronic assembly generally indicated at 20, disposed near the bottom of the base 14, regulates the current through the light bulb under the control of a control assembly, generally indicated at 22, fastened to the side of the housing 10.

More specifically, as shown in FIGS. 2 and 3, the control assembly 22 largely fits within a horizontal extension 23 that protrudes from a generally flat outer side wall 24 of the housing 10. A small rheostat 26 of the type used on printed circuit boards has a pair of tabs 260 that fit corresponding slots 24a in the side wall 24. The tabs 260, which are sufficiently short so as to not to extend all the way through the wall 24, position the rheostat 26 within the extension 23 and thereby prevent rotation of the rheostat stator after the unit is assembled. The rheostat 26 also has a pair of leads 28 and 30 soldered to terminals thereon.

The control assembly 22 also includes a coupler 32, a cover plate 34 and a control knob 36. The coupler 32 is preferably a metal stamping having an end 32a sized to fit a conventional slot (not shown) in the rotor of the rheostat 26. The assembly 22 is assembled together by first inserting the rheostat 26 into the extension 23, with the tabs 26a in the slots 24a and with the leads 28 and 30 extending through a hole 38 into the lower housing cavity 17.

The coupler end 320 is then inserted into the rheostat rotor slot and the cover plate 34 is then fitted on over the coupler 32 so that an end 32b of the coupler protrudes through a hole 34a in the cover. The plate 34 is fastened in place by a pair of drive screws 40 pushed into blind holes 42 in the housing extension 23. The cover plate 34 loosely bears against ears 32c on the coupler to retain the coupler within the rheostat rotor slot. Finally, the control knob 36 is pushed onto the coupler end 32b. The knob 36 is retained in place by virtue of a force fit with the coupler. Should the knob loosen or be removed by the user, the securely fastened plate 34 will prevent contact with the live electrical components within the extension 23.

As best seen in FIG. 2 the electronic assembly 20 includes a disk 44 of brass or other highly thermally conducting material. A triac 46 is thermally and electrically connected to the disk 44 by soldering the flat anode of the triac to the disk. A trigger diode 48 is connected to the triac gate lead 46a by means of a crimp connector 50, with the other lead of the diode 48 passing through a second crimp connector 52. The triac cathode lead 46b passes through a crimp connector 54 along with one lead of a timing capacitor 56 and a lead 58. The other lead from the capacitor 56 passes through the connector 52.

The lamp base 14 is a conventional lamp base having a base shell 59 whose bottom is filled with an insulating layer 60, generally of lime glass. In accordance with the present invention, the base is further prepared by adding a pair of tabs 62, which are fastened to the top rim of the shell 59 by soldering or welding.

With further reference to FIGS. 2 and 3, the assembly of the dimmer is completed by first inserting through a hole in the plate 19 a tab 68a integral with a socket center contact 68. The tab is then secured in place by means of a drive screw 70. Next the electronic assembly 20 is inserted into the base 14 so that the disk 44 rests upon the insulating layer 60. A brass rivet 64, which serves as a center contact for the base 14, is then inserted upwardly through a central hole in the bottom of the base and through a corresponding hole 440 in the disk 44. Then a push nut 66 is pushed down over the upper protruding end of the rivet 64 to secure the disk against the lime glass layer 60 and also to provide an electrical connection between the head of the rivet 44 and the anode of the triac 46 by way of the disk 44. Next the lead 28 from the rheostat 26 is passed into the connector 52 and the connector is crimped; the rheostat lead 30 is soldered into a hole 44b in the disk 44', and the lead 58 is soldered to the socket center contact tab 680.

In the final sequence, the base 14 is pushed up over the lower part of the housing extension 12 so as to seat against a shoulder 12a. The tabs 62, which now extend up through holes 71 into the upper cavity 16, are bent over so that their holes 62a are aligned with holes 72 in the plate 19. The shell 18, which is a conventional lamp socket shell, is then inserted into the cavity 16 with its holes 180 in alignment with the holes 620 and 72. Assembly is then completed by forcing drive screws 70 through the holes 180 and 62a and into the holes 72.

The last step locks in place both the base 14 and shell 18 without the use of an adhesive and yet securely enough to meet rigorous torque and pull-apart specifications. lt also ensures electrical contact between the shells l8 and 59. The other electrical path, from the rivet 64 to the upper center contact 68, extends through the disk 44, the anode and cathode terminals of the triac 46 and the lead 58. Overall conductivity of the latter path governs the brightness of a lamp (not shown) screwed into the shell 18. This conductivity is varied by rotating the control knob 36 to adjust the conduction angle of the triac 46.

The dimmer-adapter described above is characterized by a number of important features. It is compact, unobtrusive and easy to adjust. The intimate contact between the triac 46 and the disk 44 provides efficient heat transfer out of the triac; and contact between the disk 44 and insulating layer 60 similarly removes heat from the disk. Also, the electronic assembly is relatively isolated, thermally, from the light bulb in the shell 18. Indeed it is rather closely associated with the relatively cool socket (not shown) surrounding, and in contact with, the base 14. This promotes reliability for the electronic components in dimmer-adapter.

Finally the unit comprises inexpensive components that are readily assembled to provide a lower overall cost.

I claim:

1. A lamp dimmer-adapter comprising A. a generally cylindrical housing having I. first and second cavities at opposite ends and 2. a partition between said cavities,

B. a lamp socket shell disposed in said first cavity to receive a lamp bulb therein,

C. a lamp base across said second cavity bearing against a transverse surface of said housing and aligned with said socket shell, said base including a lamp base shell,

D. at least one tab fastened to said base shell and extending through said partition, thereby preventing relative rotational movement between said housing and said lamp base,

E. fastening means for fastening said socket shell and said tabs to said partition with said socket shell in contact with said tabs to provide electrical connection between said base and socket shells and to secure said socket shell and said base to said housing,

F. a socket center contact fastened to said partition in said first cavity and extending through said partition into said second cavity,

G. a base center contact extending from the exterior of said base into the interior thereof,

H. an electronic assembly including solid state switching means and l. disposed in said base,

2. connected to control conduction between said center contacts by means of said solid state switching means, and

3. arranged for closer thermal coupling with said base than with a lamp in said shell,

I. a control section disposed on a side of said housing,

said control section comprising 1. lateral extension of said housing having a third cavity therein,

2. a variable circuit element disposed in said third cavity,

3. a control knob for varying said circuit element,

and

J. means connecting said variable circuit element to said electronic assembly for control of the conduction of said solid state switching means by means of said variable circuit element.

2. A dimmer-adapter defined in claim 1 A. including an electrically insulating member in the bottom of said base,

B. including a metallic heat sink disk above and in contact with said electrically insulating member, said solid state switching means being in direct electrical and thermal contact with said heat sink disk,

C. in which said base center contact extends through said heat sink disk D. including resilient means fastening said disk to said second center contact, thereby to 1. position said heat sink disk against said insulating member and 2. provide an electrically conducting path from said base center contact to said switching means.

3. The dimmer-adapter defined in claim 1 A. in which said housing includes a laterally facing third cavity,

B. said control section comprises 1. a mechanically variable circuit element disposed in said third cavity,

2. a cover plate secured to said housing across said third cavity to close it,

3. a coupler connected to said circuit element and having an end extending through said cover plate,

4. a control knob mounted on said end of said coupler.

4. A lamp adapter comprising A. a generally cylindrical housing having l. first and second cavities at opposite ends and 2. a partition between said cavities,

B. a lamp socket shell disposed in said first cavity to receive a lamp bulb therein,

C. a lamp base across said second cavity and aligned with said socket shell, said base including a base shell,

D. at least one tab fastened to said base shell and extending through said partition, thereby preventing relative rotational movement between said housing and said lamp base,

E. fastening means for fastening said socket shell and said tabs to said partition with said socket shell in contact with said tabs to provide electrical connection between said base and socket shells and to secure said socket shell and said base to said housing,

F. a socket center contact fastened to said partition in said first cavity and extending through said partition into said second cavity,

G. a base center contact extending from the exterior of said base into the interior thereof,

H. an electronic assembly including solid state switching means and l. disposed in said base,

2. connected to control conduction between said center contacts by means of said solid state switching means, and

3. arranged for closer thermal coupling with said base than with a lamp in said shell,

I. a control section including an element disposed on a side of said housing,

J. means connecting said control section to said electronic assembly for control of the conduction of said solid state switching means. 

1. A lamp dimmer-adapter comprising A. a generally cylindrical housing having
 1. first and second cavities at opposite ends and
 2. a partition between said cavities, B. a lamp socket shell disposed in said first cavity to receive a lamp bulb therein, C. a lamp base across said second cavity bearing against a transverse surface of said housing and aligned with said socket shell, said base including a lamp base shell, D. at least one tab fastened to said base shell and extending through said partition, thereby preventing relative rotational movement between said housing and said lamp base, E. fastening means for fastening said socket shell and said tabs to said partition with said socket shell in contact with said tabs to provide electrical connection between said base and socket shells and to secure said socket shell and said base to said housing, F. a socket center contact fastened to said partition in said first cavity and extending through said partition into said second cavity, G. a base center contact extending from the exterior of said base into the interior thereof, H. an electronic assembly including solid state switching means and
 1. disposed in said base,
 2. connected to control conduction between said center contacts by means of said solid state switching means, and
 3. arranged for closer thermal coupling with said base than with a lamp in said shell, I. a control section disposed on a side of said housing, said control section comprising
 1. lateral extension of said housing having a third cavity therein,
 2. a variable circuit element disposed in said third cavity,
 3. a control knob for varying said circuit element, and J. means connecting said variable circuit element to said electronic assembly for control of the conduction of said solid state switching means by means of said variable circuit element.
 2. a partition between said cavities, B. a lamp socket shell disposed in said first cavity to receive a lamp bulb therein, C. a lamp base across said second cavity bearing against a transverse surface of said housing and aligned with said socket shell, said base including a lamp base shell, D. at least one tab fastened to said base shell and extending through said partition, thereby preventing relative rotational movement between said housing and said lamp base, E. fastening means for fastening said socket shell and said tabs to said partition with said socket shell in contact with said tabs to provide electrical connection between said base and socket shells and to secure said socket shell and said base to said housing, F. a socket center contact fastened to said partition in said first cavity and extending through said partition into said second cavity, G. a base center contact extending from the exterior of said base into the interior thereof, H. an electronic assembly including solid state switching means and
 2. connected to control conduction between said center contacts by means of said solid state switching means, and
 2. A dimmer-adapter defined in claim 1 A. including an electrically insulating member in the bottom of said base, B. including a metallic heat sink disk above and in contact with said electrically insulating member, said solid state switching means being in direct electrical and thermal contact with said heat sink disk, C. in which said base center contact extends through said heat sink disk D. including resilient means fastening said disk to said second center contact, thereby to
 2. a partition between said cavities, B. a lamp socket shell disposed in said first cavity to receive a lamp bulb therein, C. a lamp base across said second cavity and aligned with said socket shell, said base including a base shell, D. at least one tab fastened to said base shell and extending through said partition, thereby preventing relative rotational movement between said housing and said lamp base, E. fastening means for fastening said socket shell and said tabs to said partition with said socket shell in contact with said tabs to provide electrical connection between said base and socket shells and to secure said socket shell and said base to said housing, F. a socket center contact fastened to said partition in said first cavity and extending through said partition into said second cavity, G. a base center contact extending from the exterior of said base into the interior thereof, H. an electronic assembly including solid state switching means and
 2. provide an electrically conducting path from said base center contact to said switching means.
 2. a variable circuit element disposed in said third cavity,
 2. a cover plate secured to said housing across said third cavity to close it,
 2. connected to control conduction between said center contacts by means of said solid state switching means, and
 3. The dimmer-adapter defined in claim 1 A. in which said housing includes a laterally facing third cavity, B. said control section comprises
 3. arranged for closer thermal coupling with said base than with a lamp in said shell, I. a control section including an element disposed on a side of said housing, J. means connecting said control section to said electronic assembly for control of the conduction of said solid state switching means.
 3. a control knob for varying said circuit element, and J. means connecting said variable circuit element to said electronic assembly for control of the conduction of said solid state switching means by means of said variable circuit element.
 3. a coupler connected to said circuit element and having an end extending through said cover plate,
 3. arranged for closer thermal coupling with said base than with a lamp in said shell, I. a control section disposed on a side of said housing, said control section comprising
 4. a control knob mounted on said end of said coupler.
 4. A lamp adapter comprising A. a generally cylindrical housing having 